Vehicles have operating elements which are constructed as switches or as keys to operate various functions. A greater or lower number of such operating elements are necessary, depending on the equipment of a vehicle. In so far as vehicles do not have the entire special equipment with respect to possible operating elements, so-called blind caps are used in place of the operating elements which are not required. This has the disadvantage that, when these blind caps are used in place of the operating elements, it can be seen immediately that a vehicle does not have all the special equipment or that at least particular functions are missing.
There can also be problems with the reliability of such operating switches. If an electrical contact in an operating switch is contaminated or faulty, a user cannot operate the function associated with that operating switch.